BCG vaccination program has routine immunization program and supplementary immunization program. 1. Routine immunization program: for newborns with gestational age ≥37 weeks and birth weight ≥2500 grams, 1 dose of BCG vaccine is given after birth at a dose of 0.1 ml. 2. Supplementary immunization program: for infants born without BCG vaccination and less than 3 months old, direct supplementary vaccination; for infants between 3 months and 3 years old, tuberculin test should be done first, and those who are negative can be supplied with supplementary vaccination; children aged 4 years old and above do not need to be supplied with supplementary vaccination, and those who have already been vaccinated with BCG vaccine and have not formed the BCG scar will not be supplied with supplementary vaccination again. It should be noted that those who are allergic to the components of BCG vaccine, those who suffer from acute diseases and serious chronic diseases, immunodeficiency, immunocompromised, encephalopathy, uncontrolled epilepsy and other neurological diseases are prohibited to be vaccinated.